On December 17th, 2014, the European Chemical Agency (ECHA) added six new substances to the REACH candidate list of Substances of Very High Concern.
Health and Environmental Concerns
2-(2H-benzotriazol-2-yl)-4,6-ditertpentylphenol (UV-328) (MDTP)
Additive in plastics, UV absorber in packaging, etc.
Used as UV-absorbers for:
2-ethylhexyl 10-ethyl-4,4-dioctyl-7-oxo-8-oxa-3,5-dithia-4-stannatetradecanoate (DOTE)
Used as stabilizer for PVC processing
Used in phosphors and glass
Reaction mass of 2-ethylhexyl 10-ethyl-4,4-dioctyl-7-oxo-8-oxa-3,5-dithia-4-stannatetradecanoate and 2-ethylhexyl 10-ethyl-4-[[2-[(2-ethylhexyl)oxy]-2-oxoethyl]thio]-4-octyl-7-oxo-8-oxa-3,5-dithia-4-stannatetradecanoate (reaction mass of DOTE and MOTE)
Reprotoxic (damages fertility and unborn child)
Specifically, PBT stands for Persistent, Bioaccumulative, and Toxic. Next, vPvB stands for very Persistent and very Bioaccumulative. PBT and vPvB substances, such as PFAS, do not easily break down in the environment.
Bioaccumulation occurs when an organism consumes a chemical faster than it eliminates the substance. Thus, the chemical accumulates in the organism’s tissues. When a predator eats the organism, it receives all the collected chemicals in its prey. Therefore, the concentration of bioaccumulative substances exponentially increases up the food chain. This phenomenon is called biomagnification. Furthermore, parents pass down the chemicals to their newborns.
There are criteria that a substance must meet for it to be considered PBT or vPvB by the ECHA.
Firstly, see the difference between a persistent (P) or very persistent (vP) substance in the table below:
Criteria for Persistent (P)*
Criteria for Very Persistent (vP)*
Fresh or Estuarine Water
Fresh or Estuarine Water Sediment
* Half-life Degradation (in days) higher than…
Secondly, a substance is “bioaccumulative” when its bioconcentration factor in aquatic species is higher than 2000. A substance is “very bioaccumulative” when this factor is higher than 5000.
Finally, the ECHA considers a chemical toxic when it is:
PBTs and vPvBs are harmful to animals, plants, and humans